Tandem Solar Cell Patent Landscape 2026
Tandem Solar Cell Patent Landscape in 2026
The tandem solar cell IP field is in a Growth stage, with the three-year recent window up 39% against the prior period, though annual volume has eased from its 2022 peak. LG Chem leads the ranking, and semiconductor device IP dominates the technology mix, with Korean, Japanese, and Chinese industrial players holding most of the top positions.
LG Chem leads a moderately concentrated field with strong industrial depth
LG Chem holds the top position with 114 patent records, followed closely by LG Electronics (94), Shangrao Jinko Solar (89), SolAero Technologies (83), and Hanwha Solutions and Oxford Photovoltaics tied at 80 each. The top five filers account for 19% of the combined output of the hundred largest filers, indicating moderate rather than extreme concentration.
A clear first tier of Korean and Chinese industrial players separates from a second tier of Japanese incumbents (Toshiba, Mitsubishi Heavy Industries) and specialist pure-plays (Oxford Photovoltaics, Swift Solar). The tier gap between the leader and the tenth-ranked filer is meaningful but not insurmountable for a well-funded new entrant.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | LG Chem Ltd. | 114 | |
| 2 | LG Electronics Inc. | 94 | |
| 3 | Shangrao Jinko Solar Technology Development Co. Ltd. | 89 | |
| 4 | SolAero Technologies Corp. | 83 | |
| 5 | Hanwha Solutions Corporation | 80 | |
| 6 | Oxford Photovoltaics Ltd. | 80 | |
| 7 | Toshiba Corporation | 78 | |
| 8 | Mitsubishi Heavy Industries Ltd. | 77 | |
| 9 | TOSHIBA ENERGY SYST & SOLUTIONS CORP | 50 | |
| 10 | Zhejiang Jinko Solar Co. Ltd. | 49 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | IBM Corporation | 49 | |
| 12 | Swift Solar Inc. | 48 | |
| 13 | Jingao Solar Co. Ltd. | 44 | |
| 14 | Canon Inc. | 40 | |
| 15 | Trina Solar Co. Ltd. | 39 | |
| 16 | The Regents of the University of California | 39 | |
| 17 | Oerlikon Solar AG | 37 | |
| 18 | Alliance for Sustainable Energy LLC (NREL) | 37 | |
| 19 | KOREA INST OF SCI & TECH | 34 | |
| 20 | Kaneka Corporation | 32 |
LG Chem’s and LG Electronics’ combined position reflects vertically integrated Korean conglomerate strategy spanning materials, organic semiconductors, and system-level photovoltaic IP. Shangrao Jinko Solar’s appearance at third signals that Chinese module manufacturers are now building substantial upstream IP positions in tandem architectures.
Filing counts for 2024 and especially 2025–2026 are understated due to the standard 18-month patent publication lag; no inference should be drawn from the apparent drop in those years. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Multi-year growth persists across a broadening technology base
The annual filing trend and IPC class breakdown together show a field that expanded substantially from 2017 to 2022 and continues to attract diverse technical approaches, with semiconductor device IP as the clear core and organic semiconductor and process chemistry branches growing in relative weight.
Annual filing trend
Filings climbed from 152 in 2017 to a peak of 214 in 2022, then eased to 209 in 2023. The 2024 figure of 157 and the 2025 figure of 105 reflect publication lag and should not be read as a real contraction. On a multi-year basis the recent window remains 39% above the prior comparable window, confirming continued growth.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H01L (semiconductor devices) dominates with 2,933 patent records, far ahead of H10K (organic semiconductors, including perovskite-relevant classes) at 747 and H02S (photovoltaic power generation) at 261. The strong presence of H10K signals growing perovskite and organic tandem activity, while C23C (coating and surface deposition, 128 records) and H10F (photovoltaic and light-sensitive devices, 125 records) reflect process and device integration work.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Perovskite-silicon tandem solar cell and preparati…
Provided are a perovskite-silicon tandem solar cell and a preparation method therefor. The perovskite-silicon tandem solar cell comprises a silicon-based battery, an ITO intermediate composite layer, a first hole transport layer, a second hole transport layer, a perovskite light absorption layer, a first electron transport layer, a second electron transport… (excerpt from the patent abstract)
Open this patent in Eureka →| # | Patent | Citations |
|---|---|---|
| 1 | Method of fabricating epitaxial structures | 787 |
| 2 | Epitaxial structures on sides of a substrate | 566 |
| 3 | Optoelectronic device | 513 |
| 4 | Photovoltaic module framing system with integral e… | 491 |
| 5 | High-efficiency, monolithic, multi-bandgap, tandem… | 460 |
| 6 | Producing thin film photovoltaic modules with high… | 447 |
| 7 | Method of fabricating n-type and p-type microcryst… | 436 |
| 8 | Multijunction photovoltaic cells and panels using … | 428 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the competitive structure means for R&D investment decisions
The combination of a Growth lifecycle stage, moderate top-tier concentration, active academic-industrial co-filing, and US-dominant jurisdiction coverage creates a specific set of strategic considerations for engineers and R&D planners.
Growth stage with annual volume easing from 2022 peak
The field is classified as Growth: recent three-year filings are 39% above the prior three-year window on a multi-year basis. However, annual volume peaked in 2022 at 214 patent records and has eased since, with 2024–2025 figures further understated by publication lag. This pattern suggests the core silicon-based tandem architecture is maturing while next-generation perovskite tandem sub-fields are still injecting fresh filing momentum.
Growth · post-2022 peakModerate concentration with a two-tier field structure
The top five filers hold 19% of the hundred largest filers’ combined output, a moderate concentration level that leaves room for challengers. A clear first tier of LG Chem, LG Electronics, Jinko Solar, SolAero, and Hanwha/Oxford leads, followed by a second tier of Japanese incumbents and specialist pure-plays. Entrants with differentiated process or materials IP can still carve credible positions without displacing incumbents directly.
Moderate concentrationToshiba–Toshiba Energy the dominant co-filing pair; NREL anchors a US academic cluster
The most active co-filing relationship is between Toshiba Corporation and Toshiba Energy Systems & Solutions (46 joint records), reflecting intra-group IP coordination. Oxford Photovoltaics and Oxford University Innovation have co-filed on 6 records, linking commercial and academic perovskite research. Alliance for Sustainable Energy (NREL) co-files with Swift Solar (5 records), Colorado State University (4 records), University of Washington (2 records), and the University of California (2 records), anchoring a distributed US public-private perovskite tandem cluster. LG Electronics has one co-filing record with POSTECH.
Intra-group + national labsUS-dominant filing with Europe and PCT as secondary validation routes
The United States leads with 1,174 patent records, more than double the EPO’s 650 records. WIPO/PCT (404 records) indicates applicants are preserving broad international optionality. Japan (211), South Korea (167), and Germany (152) form a secondary protection cluster. China (123 records) is notably lower than its applicant representation in the ranking, suggesting some filers prefer US and EPO over domestic CNIPA protection for this technology.
US-first, EPO secondaryGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| Toshiba Corporation | Toshiba Energy Systems & Solutions Corporation | 46 |
| Oxford Photovoltaics Ltd. | Oxford University Innovation Ltd. | 6 |
| Mitsubishi Heavy Industries Ltd. | National Institute of Advanced Industrial Science and Technology (AIST) | 5 |
| Alliance for Sustainable Energy LLC (NREL) | Swift Solar Inc. | 5 |
| Alliance for Sustainable Energy LLC (NREL) | Colorado State University Board of Trustees | 4 |
| Alliance for Sustainable Energy LLC (NREL) | University of Washington | 2 |
| Alliance for Sustainable Energy LLC (NREL) | The Regents of the University of California | 2 |
| LG Electronics Inc. | 浦项工科大学校产学协力团 | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
LG Chem anchors materials IP; Hanwha Solutions and Swift Solar show the strongest recent momentum
The top two ranked applicants are both LG Group entities with complementary technology emphases, while momentum data reveal that several challengers are accelerating rapidly from recent entry.
LG Chem
LG Chem leads the ranking with 114 patent records, focused on H01L 31 (semiconductor devices, 106 records), H10N 10 (other electric solid-state devices, 69 records), and C01B 19 (non-metallic elements and inorganic compounds, 57 records), indicating a materials-and-device integration strategy. Its sibling entity LG Electronics (94 patent records) concentrates on H01L 31, H02S 40 (photovoltaic power generation), and H02M 7 (power conversion), covering the system side. Momentum data for LG Chem’s specific recent trend is not separately reported in the evidence.
patent records: 114Hanwha Solutions
Hanwha Solutions holds 80 patent records but is classified as a new entrant in the recent filing window, meaning substantially all of its activity is concentrated in the most recent three-year period — a striking acceleration. Its technology focus is H10K 30 and H10K 85 (organic/perovskite semiconductors, 74 and 35 records respectively) and H10F 10 (photovoltaic and light-sensitive devices, 22 records), signaling a deliberate pivot into perovskite tandem IP. Swift Solar (48 records) similarly shows strong momentum at 3.3× its prior three-year window, focused on H10K 30 organic semiconductors.
patent records: 80| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| SolAero Technologies Corp. | 10 | ▼ -63% |
| Hanwha Solutions Corporation | 58 | ▲ new entrant |
| Toshiba Corporation | 8 | ▼ -82% |
| Oxford Photovoltaics Ltd. | 11 | ▼ -50% |
| Alliance for Sustainable Energy LLC (NREL) | 13 | ▲ new entrant |
| Oxford University Innovation Ltd. | 5 | ▲ new entrant |
| Swift Solar Inc. | 36 | ▲ 3.3× vs prior 3-yr |
Under-served branches adjacent to the dominant semiconductor device core
Several IPC branches appear at relatively low share within this corpus despite plausible technical relevance to tandem solar cell development; these are observations of relative sparsity rather than confirmed commercial gaps.
H10F · Photovoltaic & light-sensitive devices
H10F covers photovoltaic and light-sensitive device architectures and accounts for 125 patent records — a 2% share relative to the dominant H01L class. As IPC reclassification progressively migrates photovoltaic subject matter from H01L into H10F, this branch is likely to grow in importance. Engineers developing next-generation tandem device structures may find relatively less crowded prior art here, particularly for thin-film and multi-junction configurations not yet fully reclassified. Searching both H01L 31 and H10F in parallel is advisable for freedom-to-operate work.
Search this in Eureka →C23C · Coating & surface deposition
C23C (coating and surface deposition) holds 128 patent records at a 2% share, despite deposition processes being central to perovskite and III-V tandem fabrication. The relative sparsity suggests that process IP for interfacial layers, anti-reflection coatings, and barrier films in tandem stacks is less contested than device-level IP. Organizations with proprietary atomic layer deposition, sputtering, or chemical vapor deposition know-how for tandem-relevant materials could find this an accessible entry vector, particularly in combination with H10K organic semiconductor claims.
Search this in Eureka →How leading applicants differ by technology route
Strength of each leader across the main technology routes.
| Player | H01L 31 · Semiconductor devices | H10K 30 · Organic semiconductors (OLED etc.) | H01L 51 · Semiconductor devices | H10K 85 · Organic semiconductors (OLED etc.) | H01L 21 · Semiconductor devices |
|---|---|---|---|---|---|
| LG Electronics Inc. | Strong · 151 | Absent | Emerging · 11 | Absent | Emerging · 6 |
| LG Chem Ltd. | Strong · 106 | Absent | Absent | Absent | Emerging · 15 |
| Oxford Photovoltaics Ltd. | Strong · 47 | Strong · 29 | Strong · 30 | Moderate · 11 | Absent |
| Oxford University Innovation Ltd. | Strong · 44 | Moderate · 20 | Strong · 27 | Moderate · 18 | Absent |
| Hanwha Solutions Corporation | Absent | Strong · 74 | Absent | Moderate · 35 | Absent |
| SolAero Technologies Corp. | Strong · 83 | Absent | Absent | Absent | Absent |
| Mitsubishi Heavy Industries Ltd. | Strong · 75 | Absent | Absent | Absent | Absent |
Frequently asked questions
The dataset covers 1,449 patent families in scope. This is the corpus on which trend, jurisdiction, and technology composition analysis is based.
LG Chem leads the ranking with 114 patent records, ahead of LG Electronics (94 records), Shangrao Jinko Solar (89 records), SolAero Technologies (83 records), and Hanwha Solutions and Oxford Photovoltaics both at 80 records.
The field is in a Growth stage: recent three-year filings are 39% above the prior three-year window on a multi-year basis. Annual volume peaked in 2022 at 214 patent records and has eased since, with 2024 and 2025 figures further understated by publication lag. The multi-year trend remains positive.
The United States leads with 1,174 patent records, followed by the EPO (650 records), WIPO/PCT (404 records), Japan (211 records), South Korea (167 records), and Germany (152 records). China receives 123 patent records despite strong Chinese applicant representation in the ranking.
Hanwha Solutions and Alliance for Sustainable Energy (NREL) are both classified as new entrants in the recent three-year window, meaning their activity is heavily concentrated in recent years. Swift Solar shows a 3.3× increase versus its prior three-year window. Conversely, Toshiba Corporation is down 82% and SolAero Technologies is down 63% in the recent period.
The most-cited patent by forward citation count is ‘Method of fabricating epitaxial structures’ (787 citations), followed by ‘Epitaxial structures on sides of a substrate’ (566), ‘Optoelectronic device’ (513), ‘Photovoltaic module framing system’ (491), and ‘High-efficiency, monolithic, multi-bandgap, tandem photovoltaics’ (460). These foundational patents reflect the III-V multi-junction and epitaxial growth heritage of the field.
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Disclaimer. This page is generated from PatSnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
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